I'm going with over training. You might need to back off on the frequency and intensity and let your body recover. More doesn't always mean better or more effective. Too much training = stress. Stress causes all kinds of problems; it inhibits weight loss, in creases anxiety, can cause sleep disturbances, and on and on. You also need adequate time for your body to recover and build muscle.
I do cardio/interval/sprinting combos 3-4 times a week (30-45 mins) at least and walk/run my dog daily weather permitting.
Also, I lift weights at least 3 times a week doing full body exercising mostly. Deadlifts, Squats, Cleans, Presses are the staples and dumbbells. I dont think I've used a machine since returning.
You might want to try weight lifting to failure (can't do any more reps) once a week for each muscle group. And as for cardio, you'd probably be better off going for long walks than running or jogging. However, what you do depends on your goals. If you're just want to be healthy and lose weight, then lots of walking and lifting once a week should work for you.
Poke it quickly, with a stick.